Intracranial Epidermoid Cysts in Three Dogs

Abstract

Abstract. Intracranial epidermoid cysts were identified within the fourth ventricle of three dogs. The cysts measured up to 2.5 cm in diameter, were lined by stratified squamous epithelium, and contained intraluminal keratinaceous debris. Secondary compression of the medulla oblongata and cerebellum caused neurologic dysfunction in two dogs; the cyst was an incidental finding in the other dog. Similarities between these dogs and three previously reported intracranial epidermoid cysts in dogs included an apparent predilection for young dogs and involvement of the cerebellopontine angle, fourth ventricle, or both.Epidermoid (epidermal) cysts are common benign skin tumors that arise from heterotopic epithelium. They are lined by squamous epithelium and contain intraluminal keratinaceous debris [ 101. Similar tumors seen intracranially in m a n are thought to occur due to inclusion of epithelial elements at the time of closure of the neural groove [3, 91. Intracranial epidermoid cysts also have been reported [6,7, 111 in three dogs (table I). However, n o detailed clinical and pathologic accounts of these dogs were given. This paper describes three additional dogs with intracranial epidermoid cysts. Materials and MethodsThe three dogs were referred to the University of Georgia Veterinary Medical Teaching Hospital for evaluation. Pertinent clinical features of these three dogs and three other reported intracranial epidermoid cysts in dogs are listed in table I. The three dogs of this report were all two years of age or less and included two males and one female. Two were English setters and one was a bloodhound. They were euthanatized due to the severity of neurologic dysfunction, and routine necropsies were done. Brains were fixed in 10% buffered formalin, serially sectioned, cut at 5 to 6 pm, and stained with hematoxylin and eosin (HE). ResultsDogs 1 and 2 had neurologic deficits compatible with a central vestibular lesion. Neurologic deficits in dog 3 were thought to be primarily cerebrocortical in origin.Hematologic and blood chemistry values were normal. Cerebrospinal fluid was evaluated in each dog: protein was elevated mildly in dogs 1 and 3, and increased 646

Intracranial Intra-arachnoid Diverticula and Cyst-like Abnormalities of the Brain

“…33 There are sporadic case reports of affected dogs that represent postmortem findings and only occasionally include attempted therapy. [34][35][36][37][38][39][40][41] Most of the intracranial canine epidermoid cysts reported have been located in the cerebellopontine/medullary angle, and can extend into the fourth ventricle 34,35,[37][38][39][40][41][42] (Fig. 2).…”

“…34 The stratified squamous epithelium lining of epidermal cysts is believed to undergo progressive exfoliation leading to an accumulation of keratinized material, cholesterol clefts, and some inflammatory cells in the lumen and subsequent expansion of the cyst. 2,42,43 The lining of the epidermoid cyst helps differentiate these structures from dermoid cysts, which have a more complex arrangement of dermis that may include hair follicles, sebaceous glands, and sweat glands. 2,37,42 Clinical Signs Neurologic signs were not reported in several dogs with central nervous system epidermoid cysts; the cyst was an incidental finding on postmortem examination 38,40,42 ; because the cysts show slow, linear growth, neurologic signs often present in middle age in humans and dogs.…”

“…2,42,43 The lining of the epidermoid cyst helps differentiate these structures from dermoid cysts, which have a more complex arrangement of dermis that may include hair follicles, sebaceous glands, and sweat glands. 2,37,42 Clinical Signs Neurologic signs were not reported in several dogs with central nervous system epidermoid cysts; the cyst was an incidental finding on postmortem examination 38,40,42 ; because the cysts show slow, linear growth, neurologic signs often present in middle age in humans and dogs. [33][34][35][36]43,44 Because of the common location of epidermoid cysts in the cerebellopontine/medullary angle, vestibular signs are frequently reported in humans and dogs [33][34][35][36][41][42][43][44][45] with up to 93% of human patients presenting with CN VIII dysfunction in one study.…”

A case of muItiloculated, intracranial epidermoid cyst in a beagle dog

“…The occurrence of intracranial epidermoid cysts is rare in dogs, and only 6 cases have been reported in the literature (McGrath, 1960;Mawdesley-Thomas & Hague, 1970;Zaki, 1977;Kornegay & Gorgacz, 1982). The condition is usually unilocular, and no further variant has been documented.…”

“Have You Seen This?” An Epidermoid Cyst with Rosette-Like Structures of the Cerebrum in a Male BALB/c Mouse

“…Epidermoid cysts in the CNS have been reported in various species such as the mouse (7,9,10), rat (7,11,12), dog (4,6,9), lamb (1), horse (5), and human (2,3). According to a previous description, the rodent epidermoid cyst is lined by strati ed squamous epithelium and lled with desquamated keratin (7,9,10,12).…”